Magnetic recording/reproducing apparatus

ABSTRACT

A magnetic recording/reproducing apparatus is disclosed that is arranged to receive a tape cassette accommodating a tape recording medium that is selectively loaded thereto. The apparatus includes a rotating drum unit having a rotating head, and a loading mechanism that is configured to pull the tape recording medium of the loaded tape cassette out of the loaded tape cassette, wind the tape recording medium around the rotating drum unit, and form a tape path. The loading mechanism includes a short loading pole that is adapted for a first tape cassette accommodating a narrow tape recording medium and a long loading pole that is adapted for a second tape cassette accommodating a wide tape recording medium, which short pole and long pole are positioned at the same height, and a loading pole raising mechanism that is configured to raise the long loading pole when the second tape cassette is loaded.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a magneticrecording/reproducing apparatus such as a streamer device that is usedas a peripheral storage device of a computer. The present inventionparticularly relates to a magnetic recording/reproducing apparatus usinga tape cassette and including a rotation drum and a tape loadingmechanism, which magnetic recording/reproducing apparatus is capable ofselectively loading a first tape cassette that accommodates a firstmagnetic tape having a first width W1 or a second tape cassette thataccommodates a second magnetic tape having a second width W2 that istwice the first width W1 of the first magnetic tape.

2. Description of the Related Art

As one type of magnetic recording/reproducing apparatus that is used asa peripheral storage device of a computer, a streamer device using atape cassette and including a rotating drum and a tape loading mechanismlike the VTR is being commercialized.

The storage capacity of a conventional streamer device is relativelylarge at around 72 GB in compression mode, for example. Yet, there is amarket demand for a streamer device with a larger storage capacity, andin turn, various manufacturers are developing new techniques forimproving the streamer device.

As one way of increasing the storage capacity of the streamer device, anew tape cassette that accommodates a magnetic tape having a tape widththat is wider than the tape width of the magnetic tape of theconventional tape cassette may be used.

SUMMARY OF THE INVENTION

In consideration of the fact that the conventional streamer device isstill used and information is recorded on the conventional tape cassetteby the conventional streamer device, it is an object of the presentinvention to provide a new streamer device that is capable of using anew tape cassette, is compatible with the conventional streamer device,is capable of using the conventional tape cassette, and is capable ofaccurately reproducing information recorded on the conventional tapecassette by the conventional streamer device.

According to an aspect of the present invention, a magneticrecording/reproducing apparatus is provided that is arranged to receivea tape cassette accommodating a tape recording medium that isselectively loaded thereto, the loaded tape cassette being selected froma plurality of types of tape cassettes including a first tape cassetteaccommodating a first tape recording medium having a first width and asecond tape cassette accommodating a second tape recording medium havinga second width that is greater than the first width, the apparatusincluding:

a rotating drum unit including a rotating head; and

a loading mechanism that is configured to pull the tape recording mediumof the loaded tape cassette out of the loaded tape cassette, wind thetape recording medium of the loaded tape cassette around the rotatingdrum unit, and form a tape path;

wherein the loading mechanism includes

a short loading pole that is adapted for the first tape cassette, and along loading pole that is adapted for the second tape cassette, theshort pole and the long pole being positioned at the same height; and

a loading pole raising mechanism that is configured to raise the longloading pole when the second tape cassette is loaded.

According to an aspect of the present invention, a long loading pole isarranged to be positioned at the same height as that of a short pole sothat a first tape cassette accommodating a narrow tape recording mediummay be suitably loaded without encountering any obstacles. When a secondtape cassette accommodating a wide tape recording medium is loaded, thelong loading pole may be raised to extend across and face the wide taperecording medium so that the wide tape recording medium may be stablypulled out without being damaged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a conventional tape cassette, a new tapecassette, and a streamer device according to an embodiment of thepresent invention in perspective view;

FIG. 2 is a diagram showing the streamer device of FIG. 1 in plan view;

FIG. 3 is a flowchart illustrating tape loading operations that areperformed when the conventional tape cassette is loaded into thestreamer device;

FIG. 4 is a flowchart illustrating tape loading operations that areperformed when the new tape cassette is loaded into the streamer device;

FIG. 5 is a diagram showing the state of the streamer device after thetape loading operations for the conventional tape cassette arecompleted;

FIG. 6 is a diagram showing the state of the streamer device after thetape loading operations for the new tape cassette are completed;

FIGS. 7A˜7C are diagrams showing a 4 mm-width magnetic tape and an 8mm-width magnetic tape that are wound onto a rotating drum unit, andtrack patterns that are formed on the magnetic tapes;

FIGS. 8A and 8B are diagrams illustrating the state of the streamerdevice when the conventional tape cassette is loaded;

FIG. 9 is a diagram illustrating the state of the streamer device aftera first operations step of FIG. 3 is completed;

FIG. 10 is a diagram illustrating the state of the streamer device aftera second operations step of FIG. 3 is completed;

FIG. 11 is a diagram illustrating the state of the streamer device aftera third operations step of FIG. 3 is completed;

FIGS. 12A and 12B are diagrams illustrating the state of the streamerdevice when the new tape cassette is loaded;

FIGS. 13A and 13B are diagrams illustrating the state of the streamerdevice when a first operations step of FIG. 4 is completed;

FIG. 14 is a diagram illustrating the state of the streamer device aftera second operations step of FIG. 4 is completed;

FIG. 15 is a diagram illustrating the state of the streamer device whena third operations step of FIG. 4 is being performed;

FIG. 16 is another diagram illustrating the state of the streamer devicewhen the third operations step of FIG. 4 is being performed;

FIG. 17 is a diagram illustrating the state of the streamer device afterthe third operations step of FIG. 4 is completed;

FIG. 18 is a diagram illustrating the state of the streamer device aftera fourth operations step of FIG. 4 is completed;

FIG. 19 is a downside perspective view of a first motion transmittingmechanism;

FIG. 20 is a perspective view showing the initial state of a pole movingmechanism;

FIG. 21 is a perspective view showing the state of the pole movingmechanism of FIG. 20 when corresponding poles are moved;

FIG. 22 is a perspective view of a second motion transmitting mechanism;

FIG. 23 is a downside perspective view of the second motion transmittingmechanism;

FIG. 24 is a plan view of the second motion transmitting mechanism;

FIGS. 25A˜25C are diagrams illustrating motion transmission to a firstdrive gear that is performed in response to a clockwise rotation of anindividual mode switching gear;

FIGS. 26A˜26C are diagrams illustrating motion transmission to a seconddrive gear that is performed in response to a counter-clockwise rotationof the individual mode switching gear;

FIGS. 27A˜27C are diagrams illustrating motion transmission to a thirddrive gear that is performed in response to a further counter-clockwiserotation of the individual mode switching gear;

FIG. 28 is a perspective view showing the initial state of another polemoving mechanism;

FIG. 29 is a perspective view showing the state of the pole movingmechanism of FIG. 28 when corresponding poles are moved;

FIG. 30 is a perspective view showing the initial state of a poleraising/lowering mechanism;

FIG. 31 is a perspective view showing the state of the poleraising/lowering mechanism of FIG. 30 when corresponding poles areraised;

FIG. 32 is an enlarged view of one portion of the pole raising/loweringmechanism of FIG. 30;

FIG. 33 is an enlarged view of another portion of the poleraising/lowering mechanism of FIG. 30;

FIG. 34 is a perspective view showing the initial state of another polemoving mechanism; and

FIG. 35 is a perspective view of the state of the pole moving mechanismof FIG. 34 when corresponding poles are moved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, principles and embodiments of the present inventionare described with reference to the accompanying drawings.

Indicated below is a list of subjects to be discussed in the followingdescription.

-   1. Outline of Streamer Device 30-   2. Structures of Tape Cassettes 10 and 20-   3. Outline of Tape Loading Operation-   4. Tape Loading Operation for Conventional Tape Cassette 10-   5. Tape Loading Operation for New Tape Cassette 20-   6. Common Operations Mechanism-   7. Common Operations-   8. Individual Operations Mechanism-   9. Individual Operations

1. [Outline of Streamer Device 30]

FIG. 1 is a diagram showing a structure of a streamer device 30according to an embodiment of the present invention. In the following,overall functions and operations of the streamer device 30 aredescribed.

FIGS. 1 and 2 illustrate the state of the streamer device 30 before atape cassette is loaded thereto. It is noted that in these drawings,directions X1-X2 represent width directions, directions Y1-Y2 representlength directions, and directions Z1-Z2 represent height directions. Thestreamer device 30 is capable of selectively loading a conventional tapecassette 10 or a new tape cassette 20, and is configured to recordinformation on a magnetic tape 14 with a width of 4 mm as well as amagnetic tape 24 with a width of 8 mm. To realize such a configuration,a rotating drum unit 31 of the streamer device 30 according to thepresent embodiment has a greater diameter D and height H compared to arotating drum unit provided in a conventional streamer device. Also, inthe streamer device 30, the winding angle for winding the magnetic tapewith a width of 8 mm onto the rotating drum unit 31 is arranged to begreater than the winding angle for the magnetic tape with a width of 4mm. As is shown in FIG. 7A, the rotating drum 31 includes a lowerstationary drum 31 a and an upper rotating drum 31 b. A rotating head isfixed to the bottom surface of the rotating drum 31 b, and a tape guide31 c for guiding the bottom edge of the magnetic tape 14/24 onto thestationary drum 31 a is provided.

The streamer device 30 includes a cassette loading mechanism (notshown), the rotating drum unit 31 having plural rotating heads, a commonoperations motor 40, a first motion transmitting mechanism 50 thattransmits the rotation of the common operations motor 40, an individualoperations motor 60, a second motion transmitting mechanism 70 thattransmits the rotation of the individual operations motor 60 in aclockwise direction to a first part and transmits the rotation of theindividual operations motor 60 in a counter-clockwise direction to asecond part, a common operations motor drive circuit 80, an individualoperations motor drive circuit 81, and a control circuit 82 including amicrocomputer, for example. The cassette loading mechanism includes ahousing that is adapted for the new tape cassette 20, and is configuredto be capable of selectively loading the conventional tape cassette 10and the new tape cassette 20. The rotating drum unit 31 is providedaround a center region of the streamer device 30, and is tilted towardthe X2 direction. The common operations motor 40 is provided at the X1side of the Y1 side edge of the streamer device 30. The individualoperations motor 60 is provided at the X2 side of the Y1 side edge ofthe streamer device 30. The first motion transmitting mechanism 50 isprovided close to the common operations motor 40, and the second motiontransmitting unit 70 is provided close to the individual operationsmotor 60. It is noted that according to the present embodiment, themotor is divided into the common operations motor 40 and the individualoperations motor 60, and the second motion transmitting mechanism 70 isconfigured to be able to switch the mechanism to which the rotation ofthe individual operations motor 60 is to be transmitted according to therotation direction thereof. In this way, a single individual operationsmotor 60 may be sufficient for operating the two different types of tapecassettes 10 and 20, and the size of the streamer device 30 may beminiaturized.

The common operations motor 40 is driven when operating a common tapeloading mechanism directed to both the magnetic tape 14 with a width of4 mm and the magnetic tape 24 with a width of 8 mm. The rotation of thecommon operations motor 40 is transmitted to the common tape loadingmechanism via the first motion transmitting mechanism 50 so that thecommon tape loading mechanism may be operated.

The individual operations motor 60 is rotated in a clockwise directionupon operating a 4 mm-width magnetic tape loading mechanism directed tothe magnetic tape 14 with a width of 4 mm. The individual operationsmotor 60 is rotated in a counter-clockwise direction upon operating an 8mm-width magnetic tape loading mechanism directed to the magnetic tape24 with a width of 8 mm. The rotation of the individual operations motor60 in the clockwise direction is transmitted to the 4 mm-width magnetictape loading mechanism via the second motion transmitting mechanism 50so that the 4 mm-width magnetic tape loading mechanism may be operated.The rotation of the individual operations motor 60 in thecounter-clockwise direction is transmitted to the 8 mm-width magnetictape loading mechanism via the second motion transmitting mechanism 50so that the 8 mm-width magnetic tape loading mechanism may be operated.

The streamer device 30 also includes loading poles P0˜P9 (simplyreferred to as ‘pole’ hereinafter), a capstan 90, a pinch roller 100,and a head cleaner 110. The poles P0, P1, P2, P3, and P9 are commonlyused by both the magnetic tapes with widths of 4 mm and 8 mm. The polesP4(4) and P5(4) are dedicated to the magnetic tape 14 with a width of 4mm, and poles P4(8), P5(8), P6, P7, and P8 are dedicated to the magnetictape 24 with a width of 8 mm. It is noted that the numbers 4 and 8 inparentheses indicate the magnetic tape widths in millimeter units. Thepoles P0, P1, P2, P3 realize the common tape loading mechanism, thepoles P4(4) and P5(4) realize the 4 mm-width magnetic tape loadingmechanism, and the poles P4(8), P5(8), P6, P7, and P8 realize the 8mm-width magnetic tape loading mechanism. As can be appreciated from theabove descriptions, according to the present embodiment, a common tapeloading mechanism that is commonly used by the magnetic tapes 14 and 24with widths of 4 mm and 8 mm, respectively, is provided, and thereby, anumber of poles may be commonly used by the magnetic tapes 14 and 24. Inthis way, the number of poles may be reduced compared to the case ofseparately providing a tape loading mechanism dedicated to the magnetictape 14 with a width of 4 mm, and a tape loading mechanism dedicated tothe magnetic tape 24 with a width of 8 mm.

Also, it is noted that the poles P0, P2, P3, P6, and P7 correspond tostationary poles, and poles P1, P4(4), P4(8), P5(8), P8, P5(4), and P9correspond to moving poles. The pole P0 is positioned at the X2 side ofa tape cassette loading portion. The poles P2 and P3 are arranged suchthat their upper ends tilt toward each other to form a pair. The polesP2 and P3 are positioned at the entrance side of the rotating drum unit31 with respect to the scanning direction of the magnetic tape, and areconfigured to provide a twist to the magnetic tape. The poles P5 and P6are arranged such that their upper ends tilt away from each other toform a pair. The poles P5 and P6 are positioned at the exit side of therotating drum unit 31 with respect to the scanning direction of themagnetic tape, and are configured to provide a twist to the magnetictape. The capstan 90 is positioned at the X1 side of the cassetteloading portion. The pinch roller 100 is normally positioned at a highposition, and is positioned close to the capstan 90. The moving polesP1, P4(4), P4(8), P5(8), P8, P5(4), and P9 are arranged within the tapecassette loading portion in this order from the X2 side to the X1 side.

Of the moving poles P1, P4(4), P4(8), P5(8), P8, P5(4), and P9, thepoles P1, P4(8), P5(8), P8, and P9 are arranged to be longer than thepoles P4(4) and P5(4). The longer poles P1, P4(8), P5(8), P8, and P9 arelowered in the Z2 direction with respect to the shorter poles P4(4) andP5(4) so that the heights of the top ends of the moving poles P1, P4(4),P4(8), P5(8), P8, P5(4), and P9 are arranged to be the same. As isdescribed in detail below, according to this arrangement, the bottomedge of the conventional tape cassette 10 may be loaded at the sameheight as that of the new tape cassette 20 without interfering with thelonger poles.

2. [Structures of Tape Cassettes 10 and 20]

In the following, the structures of the tape cassettes 10 and 20 aredescribed with reference to FIG. 1.

The conventional tape cassette 10 includes a cassette body 13 that ismade of a box structure 11, a front lid 12, and a bottom slide board(not shown) which cassette body 13 accommodates the magnetic tape 14that is wound onto a supply reel 15 and a winding reel 16, and forms atape path 17 along a rear surface of the lid 12. Also, at the front sideportion of the bottom surface of the cassette body 13, a poleaccommodating space 18 that is opened upon loading the tape cassette 10is provided. The new tape cassette 20 includes a cassette body 23 thatis made of a box structure 21, a front lid 22, and a bottom slide board(not shown) which cassette body 23 accommodates the magnetic tape 24that is wound onto a supply reel 25 and a winding reel 26, and forms atape path 27 along a rear surface of the lid 22. Also, at the front sideportion of the bottom surface of the cassette body 23, a poleaccommodating space 28 that is opened upon loading the tape cassette 20is provided. It is noted that the new tape cassette 20 is arranged tohave the same length A and width B dimensions as the conventional tapecassette 10. The height C of the new tape cassette 20 is arranged to be1.5 times the height C of the conventional tape cassette 10. Also, it isnoted that a recessed portion 29 is formed at the rear edge middleportion of the bottom surface of the box structure 21 of the new tapecassette 20.

The portion of the streamer device 30 to which the conventional tapecassette 10 and the new tape cassette 20 are loaded includes a supplyreel axle unit 32, a winding axis unit 33, and a tape cassetteidentifying switch 34. The tape cassette loading mechanisms are arrangedsuch that the height position of the bottom surface of the new tapecassette 20 upon being loaded corresponds to the loaded height positionof the bottom surface of the conventional tape cassette 10.

3. [Outline of Tape Loading Operations]

In the following, an overall description of tape loading operations ofthe streamer device 30 is given.

Referring to FIG. 3, when the conventional tape cassette 10 is loaded, aconventional tape cassette recognition operation 120, poles P1 and P9moving operations 121, poles P4(4) and P5(4) moving operations 122, apinch roller moving operation 123, and a head cleaner moving operation124 are performed in this order.

Referring to FIG. 4, when the new tape cassette 20 is loaded, a new tapecassette recognition operation 130, poles P1, P5(8), P8, and P9 raisingoperations 131, poles P1 and P9 moving operations 132, poles P5(8), P8,and P4(8) moving operations 133, a pinch roller moving operation 134,and a head cleaner moving operation 135 are performed in this order.

The poles P1 and P9 moving operations 121 and 132, the pinch rollermoving operations 123 and 134, and the head cleaner moving operations124 and 135 correspond to common operations, and are realized byrotating the common operations motor 40 in a clockwise direction.

The poles P4(4) and P5(4) moving operations 121 correspond to operationsunique to the conventional tape cassette 10. The poles P1, P5(8), P8,and P9 raising operations 131, and the poles P5(8), P8, and P4(8) movingoperations 133 correspond to operations unique to the new tape cassette20. These operations are realized by rotating the individual operationsmotor 50. Specifically, the operations 122 that are unique to theconventional tape cassette 10 are realized by rotating the individualoperations motor 50 in a counter-clockwise direction, and the operations131 and 133 that are unique to the new tape cassette 20 are realized byrotating the individual operations motor 50 in a clockwise direction. Itis noted that the circular marks in FIGS. 3 and 4 indicate the motorthat is driven and the rotating direction of the operating motor in eachof the operations 121˜124 and 131˜135.

FIGS. 5 and 11 are diagrams illustrating the state of the streamerdevice 30 after the conventional tape cassette 10 is loaded into thestreamer device 30 and the tape loading operations 121, 122, and 123 ofFIG. 3 are performed. As is shown in the drawings, the magnetic tape 14forms a tape path 17-2 (see FIG. 11). Also, as is shown in conjunctionwith FIG. 7A, the magnetic tape 14 is guided by the tape guide 31 c tobe wound onto the rotating drum unit 31 over a winding angle α1 from astart position S to an end position E1 (e.g., around 90 degrees) in adiagonal direction, and as is shown in FIG. 7B, a rotating head scansthe magnetic tape 14 in a direction indicated by arrow 162 so thatinformation may be recorded on the magnetic tape 14 in the form of atrack pattern 160 with angle θ. It is noted that the track pattern 160corresponds to a track pattern with lower compatibility that isidentical to the type of track pattern formed by a conventional streamerdevice. FIG. 7B shows the opposite side of the magnetic film surface ofthe magnetic tape 14; that is, the Y2 side of the magnetic tape 14. Theangle α1 corresponds to an angle range required for forming the trackpattern 160 across substantially the entire width of the magnetic tape14. The arrow 162 indicates the direction in which the rotating headscans the magnetic tape 14.

FIGS. 6 and 18 illustrate the state of the streamer device 30 after thenew tape cassette 20 is loaded and the tape loading operations 131, 132,133, and 134 of FIG. 4 are performed. As is shown in the drawings, themagnetic tape 24 forms a tape path 27-4 (see FIG. 18). Also, as is shownin conjunction with FIG. 7A, the magnetic tape 24 is guided by the tapeguide 31 c to be wound onto the rotating drum unit 31 over a windingangel α2 from a start position S to an end position E2 (e.g., around 180degrees) in a diagonal direction, and as is shown in FIG. 7C, therotating head scans the magnetic tape 24 in a direction indicated byarrow 163 to record information on the magnetic tape 24 in the form of atrack pattern 161 with angle θ. The track pattern 161 corresponds to anextended track pattern of the track pattern 160, and in this way, therecording capacity of the new tape cassette 20 is increased with respectto that of the conventional tape cassette 10. It is noted that FIG. 7Cshows the opposite side of a magnetic film surface of the magnetic tape24. The angle α2 corresponds to an angle range required for forming thetrack pattern 161 across substantially the entire width of the magnetictape 24. The direction of arrow 163 shown in FIG. 7C corresponds to thedirection of arrow 162 shown in FIG. 7B.

It is noted that the winding start position S for winding the magnetictape 14 onto the rotating drum unit 31 and the winding start position Sfor winding the magnetic tape 24 onto the rotating drum unit 31correspond to the same position.

4. [Tape Loading Operations for Conventional Tape Cassette 10]

In the following, tape loading operations performed in a case where theconventional tape cassette 10 is loaded are described with reference toFIGS. 8 through 11.

Referring to FIG. 2, it is noted that the streamer device 30 includespaths 140˜145 through which the corresponding poles may move, andstoppers 151, 152, and 154.

FIGS. 8A and 8B illustrate the state of the streamer device 30 when theconventional tape cassette 10 is loaded thereto. As is shown in FIG. 8B,the bottom surface of the conventional tape cassette 10 is set to heightH10 upon being loaded. When the conventional tape cassette 10 is loaded,the slide board (not shown) is slid, the supply reel 15 and the windingreel 16 are engaged by the supply reel axle unit 32 and the winding reelaxle unit 33, respectively, the lid 12 is opened, and the poles P1,P4(4), P4(8), P5(8), P8, P5(4), and P9 enter the pole accommodatingspace 18. The tape cassette identifying switch 32 is pushed by thecassette body 13, and the conventional cassette recognition operation120 is performed.

In response to the conventional cassette recognition operation 120,first, as is shown in FIG. 9, the poles P1 and P9 moving operations 121are performed. In FIG. 9, the common operations motor 40 is rotated in aclockwise direction to operate the first motion transmitting mechanism50. Accordingly, the pole P1 is moved toward the X2 direction, the poleP9 is moved toward the X1 direction, and the magnetic tape 14 is pulledout of the tape cassette 10 to form a first tape path 17-1.

Then, as is shown in FIG. 10, the poles P4(4) and P5(4) movingoperations 122 are performed. In FIG. 10, the individual operationsmotor 60 is rotated in a clockwise direction to operate the secondmotion transmitting mechanism 70. Accordingly, the pole P4(4) engages aguide rail portion 147 at the X2 side of the path 141 (see FIG. 28), andmoves along the path 141 toward the Y1 direction until reaching thestopper 151. The pole P5(4) is moved along the path 144 toward the Y1direction until reaching stopper 154. Then, the poles P4(4) and P5(4)pull the magnetic tape 14 further to extend the tape path 17-1. In turn,the magnetic tape 14 is wound around the rotating drum unit 31 over anangle α1 from the position S to the position E1 in a diagonal direction,and comes into contact with the capstan 90 to form a second tape path17-2. It is noted that the pole P5(4) and the magnetic tape 14 pass onthe Z2 side of the pinch roller 100 so as to avoid interfering with thepinch roller 100.

In the second tape path 17-2, the magnetic tape 14 extends from thesupply reel 15 of the conventional tape cassette 10, is guided by thepoles P0 and P1, is guided and twisted by the poles P2 and P3, is woundonto the rotating drum unit 31 between the poles P4(4) and P5(4), and isguided by the capstan 90 and the pole P9 to enter the winding reel 16 ofthe conventional tape cassette 10.

Then, as is shown in FIG. 11, the pinch roller moving operation 123 isperformed. In FIG. 11, the common operations motor 40 is rotated in aclockwise direction to operate the first motion transmitting mechanism50. Accordingly, the pinch roller 100 is moved downward toward the Z2direction and enters the second tape path 17-2. Then, the pinch roller100 is moved in the Xl direction to be pushed toward the capstan 90, andthe magnetic tape 14 starts running in a direction indicated by arrow139 so that an information recording or reproducing operation may bestarted.

It is noted that in the illustrated embodiment, the magnetic tape 14 iswound onto the rotating drum unit 31 until reaching the winding endposition E1. The magnetic tape 14 is separated from the peripheralsurface of the rotating drum unit 31 immediately before the rotatinghead scanning the magnetic tape 14 in a diagonal direction reaches thetop edge of the magnetic tape 14. Such an arrangement prevents therotating head from scanning across the top edge of the magnetic tape 14,and thereby, prevents damage of the magnetic tape 14 resulting from therotating head scanning across the top edge of the magnetic tape 14.

Then, the head cleaner moving operation 124 is performed. As is shown inFIG. 11, the common operations motor 40 is rotated in a clockwisedirection to operate the first motion transmitting mechanism 50.Accordingly, the head cleaner 110 is moved to a position indicated by atwo-dotted line in the drawing to come into contact with the rotatingdrum unit 31, and the rotating head is thus cleaned.

It is noted that tape unloading operations are realized by performingthe above-described operations in reverse order, in each of whichoperations the components being moved are moved in reverse directionswith respect to the moving directions indicated above.

5. [Tape Loading Operations for New Tape Cassette 20]

In the following, tape loading operations that are performed in a casewhere the new tape cassette 20 is loaded into the streamer device 30 aredescribed with reference to FIGS. 12 through 18.

FIGS. 12A and 12B illustrate the state of the streamer device 30 whenthe new tape cassette 20 is loaded thereto. As is shown in FIG. 12B, thebottom surface of the new tape cassette 20 is set to height H10 uponbeing loaded. When the new tape cassette 20 is loaded, the slide board(not shown) is slid, the supply reel 25 and the winding reel 26 areengaged by the supply reel axle unit 32 and the winding reel axle unit33, respectively, the lid 22 is opened, and the poles P1, P4(4), P4(8),P5(8), P8, P5(4), and P9 enter the pole accommodating space 28. In thiscase, the recessed portion 29 is arranged to face against the tapecassette identifying switch 32 so that the tape identifying switch 32 isnot pushed, and thus, the new cassette recognition operation 130 isperformed. Also, it is noted that when the new tape cassette 20 isloaded, the bottom edge of the magnetic tape 24 is positioned at heightH11, which corresponds to the loaded height position of the bottom edgeof the magnetic tape 14 of the conventional tape cassette 10.

In response to the new cassette recognition operation 130, first, as isshown in FIGS. 13A and 13B, the poles P1, P5(8), P8, and P9 raisingoperations 131 are performed. In FIGS. 13A and 13B, the individualoperations motor 60 is rotated in a counter-clockwise direction so thatthe second motion transmitting mechanism 70 is operated. Accordingly, apole raising/lowering mechanism 280 and other related components (seeFIG. 30) are operated so that the poles P1, P5 (8), P8, and P9 may beraised in the Z1 direction within the pole accommodating space 28 tospan across substantially the entire width of the 8 mm-width magnetictape 24. It is noted that when the poles are not arranged to faceagainst the entire width of the magnetic tape 24 upon engaging with themagnetic tape 24 to pull the magnetic tape 24 out of the new tapecassette 20, the engagement between the poles and the magnetic tape 24may be unstable to thereby cause damage to the magnetic tape 24. On theother hand, when the poles P1, P5 (8), P8, and P9 are arranged to faceagainst the entire width of the 8 mm-width magnetic tape 24, themagnetic tape 24 may be engaged without causing damage thereto.

It is noted that the upper ends of the moving poles P1, P4(4), P4(8),P5(8), P8, P5(4), and P9 are arranged to be positioned at the sameheight, and the longer poles P1, P4(8), P5(8), P8, and P9 are normallyset to lowered positions (in the Z2 direction) so that the conventionaltape cassette 10 may be loaded at the same height as the loading heightposition of the new tape cassette 20 without interfering with the longerpoles P1, P4(8), P5 (8), P8, and P9. Accordingly the operations 131 areperformed when the new tape cassette 20 is loaded into the streamerdevice 30 so as to adjust the heights of the poles for use in the newtape cassette loading operations.

Then, as is shown in FIG. 14, the poles P1 and P9 moving operations 132are performed. In FIG. 14, the common operations motor 40 is rotated ina clockwise direction to operate the first motion transmitting mechanism50. Accordingly, the pole P1 is moved toward the X2 direction, the poleP9 is moved toward the X1 direction, and the magnetic tape 24 is pulledout of the tape cassette 20 to form a first tape path 27-1.

Then, the P5(8), P8, and P4(8) moving operations are performed. First,as is shown in FIG. 15, the individual operations motor 60 is rotated ina counter-clockwise direction to operate the second motion transmittingmechanism 70. Accordingly, the poles P5(8) and P8 are moved toward theY1 direction along paths 142 and 143, respectively, to pull out themagnetic tape 24 further. In turn, the first tape path 27-1 is extendedso that the magnetic tape 24 comes into contact with the rotating drumunit 31 to form a second tape path 27-2. Then, as is shown in FIG. 16,after a certain delay, the pole P4(8) is moved toward the Y1 direction.The pole P4(8) engages a guide rail portion 146 at the X1 side of path141 to be moved along this guide rail portion 146 toward the Y1direction. The guide rail portion 146 includes a sloped portion 146asloping in the Z1 direction, and the pole P4(8) is raised in the Z1direction while being moved toward the Y1 direction to be arranged at aheight corresponding to the width of the magnetic tape 24. The poleP4(8) moves toward the Y1 direction to engage the magnetic tape 24, andcontinues moving with the magnetic tape 24 engaged thereto.

In the following, the reason for delaying the start of the operation formoving the pole P4(8) is explained. First, in order to reduce the sizeof the streamer device 30, a dedicated path is not provided for the poleP4(8), and the pole P4(8) uses the path 141, which is also used by thepole P4(4). Second, in this respect, the pole P4(8) is arranged to beraised while being moved. Third, the magnetic tape 24 is preferablydistanced as far away (in the Y1 direction) as possible from the newtape cassette 20 so that the pole P4(8) may be completely raised beforereaching the magnetic tape 24.

As is shown in FIG. 17, the poles P4(8), P5(8), and P8 reach thestoppers 151, 152, and 153, respectively, at substantially the sametime. The second tape path 27-2 is further extended to form a third tapepath 27-3 as is shown in FIG. 16, which third tape path 27-3 is furtherextended so that the magnetic tape 24 is wound around the rotating drumunit 31 over a winding angle α2 from the start position S to the endposition E2 in a diagonal direction and comes into contact with thecapstan 90 to form a fourth tape path 27-4 as is shown in FIG. 17. It isnoted that the pole P8 and the magnetic tape 24 pass the Z2 side of thepinch roller 100 without interfering with the pinch roller 100.

In the fourth tape path 27-4, the magnetic tape 24 extends from thesupply reel 25 side of the new tape cassette 20, is guided by the polesP0 and P1, is guided and twisted by the poles P2 and P3, is wound ontothe rotating drum unit 31 between the poles P4(8) and P5(8), is guidedand twisted by the poles P6 and P7, and is guided by the pole P8, thecapstan 90, and the pole P9, to then enter the winding reel 26 of thenew tape cassette 20.

Then, as is shown in FIG. 18, the pinch roller moving operation 134 isperformed. In FIG. 18, the common operations motor 40 is rotated in aclockwise direction to operate the first motion transmitting mechanism50. Accordingly, the pinch roller 100 is moved downward toward the Z2direction and enters the fourth tape path 27-4. Then, the pinch roller100 is moved in the X1 direction to be pushed toward the capstan 90, andthe magnetic tape 24 starts running in the direction indicated by arrow139 so that an information recording or reproducing operation may bestarted.

It is noted that in the illustrated embodiment, the magnetic tape 24 iswound onto the rotating drum unit 31 until reaching the winding endposition E2. The magnetic tape 24 is separated from the peripheralsurface of the rotating drum unit 31 immediately before the rotatinghead scanning the magnetic tape 24 in a diagonal direction reaches thetop edge of the magnetic tape 24. Such an arrangement prevents therotating head from scanning across the top edge of the magnetic tape 24,and thereby prevents damage of the magnetic tape 24 resulting from therotating head scanning across the top edge of the magnetic tape 24.

Then, the head cleaner moving operation 135 is performed. As is shown inFIG. 18, the common operations motor 40 is rotated in a clockwisedirection to operate the first motion transmitting mechanism 50.Accordingly, the head cleaner 110 is moved to a position indicated by atwo-dotted line in the drawing to come into contact with the rotatingdrum unit 31, and the rotating head is thus cleaned.

It is noted that tape unloading operations are realized by performingthe above-described operations in reverse order, in each of whichoperations the components being moved are moved in reverse directionswith respect to the moving directions indicated above.

Also, it is noted that in the illustrated embodiment, the magnetic tape14/24 is twisted by the stationary poles P2 and P3 before being woundonto the rotating drum unit 31, and the perpendicular pole P4(4/8) movesto pull out the magnetic tape 14/24 and position the magnetic tape 14/24alongside the rotating drum unit 31 and determines the position of themagnetic tape 14/24 at the entrance side of the rotating drum unit 31.Also, the magnetic tape 14/24 is twisted by the stationary poles P6 andP7 after separating from the rotating drum unit 31, and the pole P5(4/8)moves to pull out the magnetic tape 14/24 and determines the position ofthe magnetic tape 14/24 at the exit side of the rotating drum unit 31.By realizing such an arrangement, the moving poles P1, P4(4), P4(8),P5(8), P8, P5(4), and P9 may be accommodated within the poleaccommodating space 18/28.

6. [Common Operations Mechanism]

In the following, the common operations motor 40, the first motiontransmitting mechanism 50, and operations and mechanisms that arecontrolled by the power transmitted from the first motion transmissionmechanism 50 are described.

FIG. 19 illustrates the state of the first motion transmitting mechanism50 when the streamer device 30 is in the state as is illustrated by FIG.1 (i.e., when a tape cassette is not loaded). FIG. 19 is a downsideperspective view of the first motion transmitting mechanism 50.According to this drawing, the first motion transmitting mechanism 50includes an operation state detection substrate 170 that is providedwith plural photo detectors, and a common mode switching gear 171 thathas a mode switching pattern formed on its lower surface and a cam 172provided on its upper surface. The operation state detection substrate170 optically detects a rotation angle position of the common modeswitching gear 171 based on the combination of outputs from the photodetectors, and detects the operation state of the first motiontransmitting mechanism 50. In turn, as is shown in FIG. 2, a detectionsignal is transmitted from the operation state detection substrate 170to a control circuit 82, and a control signal is transmitted from thecontrol circuit 82 to a motor drive circuit 80 so that the motor drivecircuit 80 may be operated. In turn, the common operations motor 40 isactivated and deactivated at predetermined timings to perform the polesP1 and P9 moving operations 121, 131, the pinch roller moving operations123, 134 and the head cleaner moving operations 124, 135 of FIGS. 3 and4. The first motion transmitting mechanism 50 also includes a tapecassette loading arm 173 that is rotated by the cam unit 172 and isconfigured to operate a tape cassette loading mechanism (not shown). Itis noted that in the illustrated embodiment, the common mode switchinggear itself is provided with a mode switching function, and in this way,the mode position may be accurately determined compared to anarrangement in which the mode switching function is provided elsewhere.

7. [Common Operations]

[Poles P1 and P9 Moving Operations 121/131] (see FIGS. 20 and 21)

FIGS. 20 and 21 are diagrams showing states of a pole moving mechanismfor the poles P1 and P9.

As is shown in FIGS. 20 and 21, the pole P1 is fixed to the tip portionof arm 181. A sleeve 182 is fixed to the base portion of the arm 181,and this sleeve 182 is rotatably and slidably engaged and supported by astationary post 186 (see FIG. 30) that is fixed to a chassis base. Asleeve 185 is fixed to the base portion of the arm 183, and this sleeve185 is rotatably and slidably engaged and supported by a stationary post187 (see FIG. 30) that is fixed to the chassis base.

When the common operations motor 40 is driven, a gear mechanism 174 isdriven via a worm gear 41 (see FIG. 19), a drive gear 175 is rotated ina clockwise direction (see FIG. 20), a slide lever 176 is slid in the Y2direction, and a slide lever 180 is slid in the Y2 direction via arotating lever 177, a link 178, and a rotating lever 179 (see FIG. 21).In response to the sliding motion of the slide lever 180, the arm 181 isrotated in a counter-clockwise direction around the stationary post 186and the pole P1 is thus moved. Also, in response to the sliding motionof the slide lever 176, the arms 184 and 183 are rotated in a clockwisedirection around the stationary post 187 and the pole P9 is thus moved.

[Pinch Roller Moving Operation 123/134] (see FIG. 19)

When the common operations motor 40 is driven, a cylinder portion 102 atthe base of a pinch roller support arm 101 is guided by a perpendiculartrench to be lowered in the Z2 direction, and upon reaching the end ofthe perpendicular trench, the pinch roller support arm 101 is rotated ina direction indicated by arrow 193. In this way, the pinch roller 100 ispushed toward the capstan 90.

[Head Cleaner Moving Operation 124/135] (see FIG. 19)

When the common operations motor 40 is driven, the common mode switchinggear 171 is rotated, and an arm member 111 is rotated by the cam 172that is provided at the common mode switching gear 171 so that the headcleaner 110 is moved to come into contact with the rotating drum unit31.

It is noted that after the common mode switching gear 171 is rotated andthe head cleaner 110 is moved accordingly, the common mode switchinggear 171 may be rotated in a reverse direction, and the above describedoperations may be performed in reverse order (i.e., 124/135, 123/134,121/131) in which case the components moved in each operation are movedin reverse directions with respect to the moving directions indicatedabove. In this way, the mechanisms described above may be set back totheir initial states.

8. [Individual Operations Mechanism]

In the following, the individual operations motor 60, the second motiontransmitting mechanism 70, and operations and mechanisms controlled bythe power transmitted from the second motion transmitting mechanism aredescribed.

FIGS. 22, 23, and 24 illustrate the second motion transmitting mechanism70 of the streamer device 30. FIG. 22 is a perspective view of thesecond motion transmitting mechanism 70 from the upper side, FIG. 23 isa perspective view of the second motion transmitting mechanism 70 fromthe lower side, and FIG. 24 is a diagram showing the state of the secondmotion transmitting mechanism 70 when the streamer device 30 is in thestate as is shown in FIG. 1, such a state being referred to as initialstate hereinafter. It is noted that FIG. 22 shows the state of thesecond motion transmitting mechanism 70 after the poles P1, P5(8), P8,and P9 moving operations 131 are completed.

As is shown in FIGS. 22, 23, and 24, the second motion transmittingmechanism 70 includes an individual mode switching gear 200, a firstdrive gear 210, a second drive gear 220, a third drive gear 230, and anoperation state detection substrate 240. The mode switching gear 200 isprovided at the Z2 side of the common mode switching gear 171 and isarranged to be coaxial with the common mode switching gear 171. Thefirst, second, and third drive gears 210, 220, and 230 are provided inthe vicinity of the individual mode switching gear 200, and as isdescribed in detail below, these drive gears 210, 220, and 230 arearranged to be temporarily driven at different timings in response tothe rotation of the individual mode switching gear 200. It is noted thata mode switching pattern 209 is formed at the lower surface of theindividual mode switching gear 200, and the operation state detectionsubstrate 204 includes plural photo detectors. The operation statedetection substrate 204 optically detects the rotation angle position ofthe individual mode switching gear 200 based on the combination ofoutputs from the photo detectors to detect the operation state of thesecond motion transmitting mechanism 70.

As is shown in FIG. 2, a detection signal is transmitted from theoperation state detection substrate 240 to the control circuit 82, and acontrol signal is transmitted from the control circuit 82 to the motordrive circuit 81. Accordingly, the motor drive circuit 81 is operatedand the individual operations motor 60 is activated and deactivated atpredetermined timings to realize the poles P4(4) and P5(4) movingoperations 122 of FIG. 3, the poles P1, P5(8), and P9 raising operations131, and the poles P5(8), P8, and P4(8) moving operations 133 of FIG. 4.It is noted that in the illustrated embodiment, the individual modeswitching gear itself is provided with a mode switching function, andthereby, the mode position may be accurately determined compared to anarrangement in which the mode switching function is provided elsewhere.

The individual mode switching gear 200 includes a gear portion 201, arecessed portion 202, and an arc-shaped recessed portion 203. Also, apartial gear portion 205 and a cam portion 206 are provided on thesurface of the individual mode switching gear 200 to form a steppedarrangement. The recessed portion 202 and the arc-shaped recessedportion 203 are formed by cutting a Z2-side half section of the gearportion 201. The recessed portion 202 and the arc-shaped recessedportion 203 are positioned next to each other with a protruding portion207 provided therebetween. The arc-shaped recessed portion 203 extendsover an angle of approximately 120 degrees. The gear portion 201includes a full-length gear portion 201 a and a half-length gear portion201 b. The cam portion 206 includes a recessed portion 206a, anarc-shaped recessed portion 206 b, and a pin portion 206 c provided nextto the recessed portion 206 a.

The first drive gear 210 includes a partial gear portion 211 and aprotruding portion 212 at one end of the partial gear portion 211. Inthe initial state, the partial gear portion 211 is not engaged with thepartial gear portion 205. The first drive gear 210 may be rotated by apredetermined angle to realize the poles P4(4) and P5(4) movingoperations 122.

The second drive gear 220 includes three protruding portions 221, 222,and 223. Also, an arc-shaped recessed portion 224 is formed between theprotruding portions 221 and 223. The protruding portion 222 is providedaround the center of the arc-shaped recessed portion 224, and protrudesfrom the upper surface edge of the second drive gear 220. In the initialstate, the protruding portion 221 is engaged by the recessed portion206a. The second drive gear 220 may be rotated by a predetermined angleto realize the poles P1, P5(8), P8, and P9 raising operations 131.

The third drive gear 230 includes an upper drive gear 235, a lower drivegear 236, and a helical torsion spring 237 that is provided between theupper and lower drive gears 235 and 236. Normally, the upper drive gear235 and the lower drive gear 236 are rotated integrally. The upper drivegear 235 includes a gear portion 235 a across the entire periphery ofthe upper drive gear 235. The lower drive gear 236 includes a gearportion 231 that extends across approximately a 270-degree angle, andfirst and second protruding portions 232 and 233 protruding in an outerradial direction. The first and second protruding portions 232 and 233are slightly set apart from each other. The first protruding portion 232is arranged to correspond to the depth of the recessed portion 202, andthe second protruding portion 233 is arranged to correspond to the depthof the arc-shaped recessed portion 203 (i.e, the first protrudingportion 232 protrudes higher than the second protruding portion 233). Inthe initial state, the second protruding portion 233 is engaged with thearc-shaped recessed portion 203, and the partial gear portion 231 is notengaged with the gear portion 201. The third drive gear 230 may berotated by a predetermined angle to realize the pole P5(8), P8, andP4(8) moving operations 133. The helical torsion spring 237 is twistedat the last stage of the operation to generate a force for urging thepoles P5(8), P8, and P4(8) to their corresponding stoppers.

In the following, rotation transmitting operations for transmitting arotational motion from the individual mode switching gear 200 to thefirst, second, and third drive gears 210, 220, and 230 are described.

When the individual operations motor 60 is driven to rotate in aclockwise direction, the rotation is transmitted via the worm gearmechanism 61, and the individual mode switching gear 200 is rotated in aclockwise direction by approximately 30 degrees. When the individualoperations motor 60 is rotated in the reverse direction, namely, in acounter-clockwise direction, the individual mode switching gear 200 isrotated in a counter-clockwise direction by approximately 360 degrees.

When the individual mode switching gear 200 is rotated from the initialstate in a clockwise direction by a predetermined angle, the protrudingportion 212 is pushed, the gear portion 205 engages the partial gearportion 211 (see FIG. 25A), and the first drive gear 210 is rotated in acounter-clockwise direction (see FIG. 25B) to reach the position as isindicated in FIG. 25C. It is noted that during this operation, thesecond and third drive gears 220 and 230 are maintained at standstillstates. When the individual mode switching gear 200 is rotated in adirection for returning to the initial state from the rotated state, thefirst drive gear 210 is rotated in a clockwise direction to be set backto the initial state.

Also, when the individual mode switching gear 200 is rotated from theinitial state in a counter-clockwise direction by a predetermined angle,the protruding portion 221 is pushed by the edge of the recessed portion206 a, and the second drive gear 220 is rotated in a clockwise directionby a predetermined angle (see FIG. 26A). When the second drive gear 220is rotated and the protruding portion 221 passes the recessed portion206 a, the recessed portion 224 faces the cam portion 206, and thesecond drive gear 220 is maintained at this position thereinafter. Inthis state, the protruding portion 222 is positioned at the uppersurface side of the cam portion 206.

When the individual mode switching gear 200 is rotated further in acounter-clockwise direction, the edge of the arc-shaped recessed portion203 pushes the second protruding portion 233 to induce an initialrotation of the third drive gear 230 (see FIG. 26B). Then, as is shownin FIG. 26C, the gear portion 201 a and the gear portion 231 are engagedwith each other, and the third drive gear 230 is rotated in a clockwisedirection. When the third drive gear 230 is rotated by approximately 270degrees, the first protruding portion 232 enters the recessed portion202 (see FIG. 27A), the protruding portion 207 pushes the firstprotruding portion 232 (see FIG. 27B), and the rotation of the thirddrive gear 230 is transmitted with a strong force to reach a finalposition as is shown in FIG. 27C. In this state, the first protrudingportion 232 is positioned past the recessed portion 202 and the secondprotruding portion 233 is inserted into the arc-shaped recessed portion203. It is noted that during this operation, the first drive gear 210 ismaintained at a standstill state.

When the individual mode switching gear 200 is rotated in a directionfor returning to the initial state from the rotated state, first, thethird drive gear 230 is rotated in a counter-clockwise direction to beset back to the initial state. Then, the pin portion 206 c pushes theprotruding portion 222, and the second drive gear 220 is rotated in acounter-clockwise direction to return to the initial state.

9. [Individual Operations]

In the following, the operations 121, 131, and 133 are described indetail.

[Poles P4(4) and P5(4) Moving Operations 122] (see FIGS. 28 and 29)

FIG. 28 shows the initial state of a pole moving mechanism for movingthe poles P4(4) and P5(4). FIG. 29 shows the state of the pole movingmechanism after the poles P4(4) and P5(4) are moved. When the firstdrive gear 210 is rotated in a counter-clockwise direction by theindividual mode switching gear 200, a slide lever 250 is slid in the Y2direction, and a slide lever 252 is slid in the X2 direction via arotation lever 251. In response to the sliding motion of the slide lever252, first, a rotating lever 253 is rotated in a clockwise directionaround a stationary axis 254, and a rotating lever 256 is rotated in acounter-clockwise direction around a stationary axle 257 via a link 255.The rotational force of the rotating lever 256 is transmitted to thepole P(4) via a link 258, and the pole P4(4) moves in the Y1 directionalong the guide rail portion 147 until reaching the position of thestopper 151 as is shown in FIG. 29. Second, in response to the slidingmotion of the slide lever 252, a rotating lever 260 is rotated in aclockwise direction around a stationary axle 261, and this rotation istransmitted to the pole P5(4) via a link 262. In turn, the pole P5(4)moves in the Y1 direction until reaching the position of the stopper 154as is shown in FIG. 29.

When the first drive gear 210 is rotated in a clockwise direction fromthe rotated state, the pole moving mechanism for the poles P4(4) andP5(4) is set back to the initial state as is shown in FIG. 28 from thestate shown in FIG. 29.

[Poles P1, P5(8), P8, and P9 Raising Operations] (see FIGS. 30 though33)

FIG. 30 shows the initial state of a pole raising/lowering mechanism forthe poles P1, P5(8), P8, and P9. FIG. 31 shows the state of the poleraising/lowering mechanism after the poles P1, P5(8), P8, and P9 areraised.

When the second drive gear 220 is rotated in a clockwise direction bythe individual mode switching gear 200, a slide lever 300 is slid in theY1 direction, and a slide lever 302 is slid in the Xl direction via arotating lever 301. The slide lever 300 includes a cam trench 304, andthe slide lever 302 includes racks 305 and 306.

It is noted that a see-saw type pole raising/lowering mechanism 270 isprovided for the pole P1, a spiral cam type pole raising/loweringmechanism 280 is provided for the poles P5(8) and P8, and a spiral camtype pole raising/lowering mechanism 290 is provided for the pole P9.

The pole raising/lowering mechanism 270 includes a lever 271 having acenter axle 272 that is supported by a bracket 275 to oscillate back andforth. A pin 273 at the Y1 side end of the lever 271 is engaged with thecam trench 304 of the slide lever 300, and a forked portion at the Y2side end of the lever 271 is connected to the sleeve 182.

When the slide lever 300 is slid in the Y1 direction, the lever 271 isrotated by the cam trench 304 in a direction that causes the forkedportion 274 to be raised, and the sleeve 182 is moved in the Z1direction along the stationary post 186 so that the pole P1 is raised(see FIG. 31).

The pole raising/lowering mechanism 280 includes a spiral cam member 281and a raising/lowering member 285 (see FIG. 32). The spiral cam member281 has a spiral cam trench 282 formed around its cylindrical portion,and a gear 283 provided at its bottom portion. The spiral cam member 281is engaged and supported by a stationary post that is fixed to thechassis base. The gear 283 is engaged with the rack 305 of the slidelever 203. The raising/lowering member 285 includes a cylindricalportion 286 that is engaged with the spiral cam member 281, a camfollower 287 that is engaged with the spiral cam trench 282, and aU-shaped trench portion 288 that is engaged by and fit to a stationarypost 307 that is fixed to the chassis base. A stage 289 (see FIG. 31) isfixed to the upper surface of the raising/lowering member 285, and thepoles P5(8) and P8 are supported by the stage 289.

As is shown in FIG. 31, when the slide lever 302 is slid in the X1direction, the spiral cam member 281 is rotated in a clockwise directionby the rack 305, the cam follower 287 is guided by the spiral cam trench282, the raising/lowering member 285 is moved in the Z1 direction, andthe poles P5(8) and P8 are raised along with the stage 289. It is notedthat the poles P5(8) and P8 may be raised by moving one end of links 340and 342 shown in FIG. 34.

The pole raising/lowering mechanism 290 has a same structure as that ofthe pole raising/lowering mechanism 280. As is shown in FIG. 33, thepole raising/lowering mechanism 290 includes a spiral cam member 291 anda raising/lowering member 295. The spiral cam member 291 is engaged andsupported by a stationary post that is fixed to the chassis base, andincludes a gear 293 that is engaged with the rack 306. Theraising/lowering member 295 includes a cylindrical portion 296 that isengaged with the spiral cam member 291, a cam follower 297 that isengaged with the spiral cam trench 292, and a U-shaped trench portion298 that is engaged by and fit to a stationary post 308 that is fixed tothe chassis base. A stage 299 (see FIG. 31) is fixed to the uppersurface of the raising/lowering member 295, and the stage 299 supportsthe arms 183 and 184 (see FIG. 21).

As is shown in FIG. 31, when the slide lever 302 is slid in the X1direction, the spiral cam member 291 is rotated in a counter-clockwisedirection by the rack 306, the cam follower 297 is guided by the spiralcam trench 292, the raising/lowering member 295 and the stage 299 aremoved in the Z1 direction, the arms 183 and 184 are raised by the stage299, the sleeve 185 is slid in the Z1 direction along the stationarypost 187, and the pole P9 is raised along with the arms 183 and 184.

When the second drive gear 220 is rotated in a counter-clockwisedirection from the rotated state, the pole raising/lowering mechanism isset back to the initial state as is shown in FIG. 30 from the stateshown in FIG. 31.

[Poles P5(8), P8, and P4(8) Moving Operations 133] (see FIGS. 34 and 35)

FIG. 34 shows the initial state of a pole moving mechanism for the polesP5(8), P8, and P4(8). FIG. 35 shows the state of the pole movingmechanism after the poles P5(8), P8, and P4(8) are moved.

The pole moving mechanism of FIGS. 34 and 35 includes a ring structure310. The ring structure 310 is supported by the chassis base at itsinner circumferential area, and is arranged to surround the rotatingdrum unit 31. The ring structure 310 includes a first ring member 311and a second ring member 312 that face each other and are attachedtogether by arc-shaped holes and pins. The first and second ring members311 and 312 are arranged to be able to rotate relative to each otherover a predetermined angle range, and are pulled in one direction by atension spring 313 to form an integral structure. It is noted that agear portion 314 is formed at the first ring member 311 across apredetermined angle range, and the gear portion 235 a of the third drivegear 230 and the gear portion 314 of the ring structure 310 are arrangedto be engaged with one another.

As is shown in the drawings, a fan-shaped gear 320 that includes a gearportion 321 and is supported by a stationary post 322 extending from thechassis base is positioned at the X2 side of the ring structure 310. Aprotruding portion 325 is provided at an edge of the gear portion 321.

Also, a slide board 330 that is arranged to slide in the Y1 direction isengaged with the fan-shaped gear 320. The slide board 330 includes anelongated hole 331 into which the tip of a pin 324 of an arm portion 323of the fan-shaped gear 320 is inserted to realize the engagement betweenthe slide board 330 and the fan-shaped gear 320.

The pole P5(8) is connected to the first ring member 311 via the link340. The pole P8 is connected to the second ring member 312 via the link342. A rotating arm 343 is supported by a stationary post extending fromthe chassis base, and the pole P4(8) is connected to the tip of therotating arm 343 via a link 345. A pin 346 is provided at a middlesection of the rotating arm 343, and the pin 346 is engaged with aU-shaped cut portion 332 of the slide board 330.

When the third drive gear 230 is rotated in a clockwise direction by theindividual mode switching gear 200, the ring structure 310 is rotated ina counter-clockwise direction owing to the engagement between the gearportion 235 a and the gear portion 314 so that the poles P5(8) and P8start moving. At a point where the poles P5(8) and P8 are still beingmoved, the protruding portion 325 is pushed by a protruding portion ofthe ring structure 310 to induce the initial rotation of the fan-shapedgear 320 in a clockwise direction. Then, the gear portion 314 engagesthe gear portion 321, the fan-shaped gear 320 is rotated in a clockwisedirection, the slide board 330 is slid in the Y1 direction, the rotatingarm 343 is rotated in a counter-clockwise direction, the link 345 ispushed, and the pole P4(8) starts moving.

As is shown in FIG. 35, the poles P5(8), P8, and P4(8) move untilreaching the stoppers 152, 153, and 151, respectively. At this point,the first ring member 311 may not rotate any further in acounter-clockwise direction, and since the gear portion 235 a and thegear portion 314 engage with one another, the upper drive gear 235 ofthe third drive gear 230 may not rotate any further. The rotation of theindividual mode switching gear 200 continues for some time, and in turn,only the lower drive gear 236 of the third drive gear 230 rotates in aclockwise direction while twisting the helical torsion spring 237. Whenthe rotation of the individual mode switching gear 200 is stopped, thespring force of the helical torsion spring 237 is transmitted via theupper drive gear 235 to the ring structure 310 and the fan-shaped gear320. In turn, the ring structure 310 is urged toward a counter-clockwisedirection, and the pole P5(8) is pushed to the stopper 152 by thisforce. Also, the fan-shaped gear 320 is urged toward a clockwisedirection, and the pole P4(8) is pushed to the stopper 151 by thisforce. The pole P8 is urged to the stopper 153 by the spring force ofthe tension spring 313 of the ring structure 310.

When the third drive gear 230 is rotated in a counter-clockwisedirection from the rotated position, the pole moving mechanism in thestate shown in FIG. 35 is set back to the initial state shown in FIG.34.

Also, it is noted that in the illustrated embodiment, the common mode isindependently determined by the common mode switching gear 171, and theindividual mode is independently determined by the individual modeswitching gear 200. Therefore, the order of performing common modeoperations and individual mode operations may be easily changed withsoftware, for example.

Further, it is noted that the present invention is not limited to thespecific embodiments described above, and variations and modificationsmay be made without departing from the scope of the present invention.For example, the present invention may be applied to arecording/reproducing device using a magnetic tape other than a streamerdevice.

The present application is based on and claims the benefit of theearlier filing date of Japanese Patent Application No. 2004-288244 filedon Sep. 30, 2004, the entire contents of which are hereby incorporatedby reference.

1. A magnetic recording/reproducing apparatus that is arranged toreceive a tape cassette accommodating a tape recording medium that isselectively loaded thereto, the loaded tape cassette being selected froma plurality of types of tape cassettes including a first tape cassetteaccommodating a first tape recording medium having a first width and asecond tape cassette accommodating a second tape recording medium havinga second width that is greater than the first width, the apparatuscomprising: a rotating drum unit including a rotating head; and aloading mechanism that is configured to pull the tape recording mediumof the loaded tape cassette out of the loaded tape cassette, wind thetape recording medium of the loaded tape cassette around the rotatingdrum unit, and form a tape path; wherein the loading mechanism includesa short loading pole that is adapted for the first tape cassette, and along loading pole that is adapted for the second tape cassette, theshort pole and the long pole being positioned at a same height; and aloading pole raising mechanism that is configured to raise the longloading pole when the second tape cassette is loaded.
 2. The magneticrecording/reproducing apparatus as claimed in claim 1, wherein theloading pole raising mechanism includes an oscillating lever; and whenthe oscillating lever is oscillated, the long loading pole is raised byan end portion of the oscillating lever.
 3. The magneticrecording/reproducing apparatus as claimed in claim 1, wherein theloading pole raising mechanism includes a spiral cam member having acylindrical portion and a spiral cam trench formed around thecylindrical portion; and a raising/lowering member having a cam followerthat is engaged with the spiral cam trench, which raising/loweringmember is slidably supported by the spiral cam member; and when thespiral cam member is rotated, the cam follower is guided by the spiralcam trench, and the raising/lowering member is raised to cause the longloading pole to be raised.
 4. The magnetic recording/reproducingapparatus as claimed in claim 1, wherein the loading pole raisingmechanism includes a guide rail portion that is configured to guide thelong loading pole when said long loading pole is moved, the guide railportion including a sloped portion that slopes in an upward direction.